JPWO2006129472A1 - Capsule endoscope - Google Patents

Abstract

The present invention has a tablet capsule shape in which an objective lens, an illumination light source unit, a solid-state imaging device and the like are integrated, and smoothly progresses in the digestive organ in any body cavity digestive device, and has excellent durability, and Provided is a capsule endoscope for medical use capable of obtaining a clear image. The medical capsule endoscope of the present invention is characterized by having a surface portion A having a wetting index of 40 mN / m or more.

Description

  The present invention relates to a capsule endoscope. Specifically, the capsule endoscope has a tablet capsule shape in which an objective lens, an illumination light source unit, a solid-state imaging device, and the like are integrally incorporated, and the digestive organ can be smoothly moved in any digestive organ in a body cavity. In particular, the present invention relates to a medical capsule endoscope that can obtain a clear image.

  Currently, fiberscopes and electronic endoscope devices are widely used in the medical field for diagnosis and treatment in body cavities. These devices have a tubular insertion portion having an image pickup device or the like at the tip, an operation portion connected to the insertion portion, an image processing device connected to the insertion portion, a display device, and the like. An endoscope apparatus that can be inserted into a body cavity of a subject and imaged to observe and inspect a desired site in the body cavity. Such an endoscopic device is practiced by practicing from the thickness and length of the insertion part inserted into the body cavity, complicated shape, etc., and a skilled doctor or engineer operates the device to perform observation, inspection, etc. There was a need to do. In addition, these endoscope apparatuses are accompanied by pain of the subject when inserted into the body cavity.

In response to the above problems, in recent years, a so-called capsule endoscope has been developed in which a solid-state image pickup device having a photographing optical system and the like is housed in a tablet capsule-shaped housing. This capsule endoscope is easily inserted into a body cavity by, for example, the subject swallowing it, images the affected area, transmits the image data from the body, and receives it outside the body, Observation and inspection of organs such as the small intestine were also facilitated (see, for example, Patent Document 1).
JP 7-289504 A

  However, in order to capture the inside of the body cavity smoothly, a design suitable for the inner surface of the digestive tract where the digestive juice is secreted is required, but the idea is focused solely on the property of good hydrophilicity. The current situation is. Even when the surface member of the capsule endoscope is in a hydrophilic state, when it passes through the stomach, it is under strong acidity of pH 1-2, and in contrast, it is neutral or weakly alkaline in the small intestine and large intestine. In addition, the digestive organs and secretions cover the lens surface and the surface of the luminaire by the digestive organs, causing a decrease in transmittance and a decrease in the amount of luminescence, thereby blurring the captured image. In addition, due to the adhesiveness of digestive juices and secretions and the degree of unevenness of the inner surface of the digestive organ, the digestive organ does not proceed smoothly, resulting in a decrease in the sharpness of the captured image.

  The present invention has been made in view of the above-mentioned problems, and its purpose is a tablet capsule shape in which an objective lens, an illumination light source unit, a solid-state imaging device, and the like are integrally incorporated, and digestion is performed in any of the body cavity digestive organs. It is an object of the present invention to provide a medical capsule endoscope that can smoothly travel in a vessel, has excellent durability, and provides a clear image.

  The above object of the present invention is achieved by the following configurations.

  1. A capsule endoscope having a surface portion A having a wetting index of 40 mN / m or more.

  2. 2. The capsule endoscope according to 1 above, wherein the surface portion A is a protective member of an imaging unit that houses a lens and an illuminating body.

  3. 2. The capsule endoscope according to 1, wherein the surface portion A is a lens surface or an illuminator surface.

  4). 4. The capsule endoscope according to any one of claims 1 to 3, wherein the surface portion A is subjected to corona discharge treatment or plasma discharge treatment.

  5. 5. The capsule endoscope according to any one of claims 1 to 4, wherein the material constituting the surface portion A is a polymer having a nonionic group or an anionic group.

  6). 6. The capsule endoscope according to 5, wherein the nonionic group is at least one selected from a single hydroxyl group, a sugar chain structure having a plurality of hydroxyl groups, and an alkylene oxide group.

  7. 6. The capsule endoscope according to 5, wherein the anionic group is a sulfonic acid group or a phosphoric acid group.

  According to the present invention, it has a tablet capsule shape in which an objective lens, an illumination light source unit, a solid-state imaging device and the like are integrally incorporated, and smoothly progresses in the digestive organ in any body cavity digestive device, and has excellent durability. In addition, it is possible to provide a medical capsule endoscope that can obtain a clear image.

It is a whole schematic diagram showing an example of an embodiment of a capsule endoscope of the present invention. It is the whole schematic figure which shows another example of embodiment of the capsule endoscope of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capsule endoscope polymer housing 2 Objective lens 3 Imaging element 4 Light emitting module 5 Light source unit 6 Transmitting unit 7 Receiving unit 8 Antenna 9 Power storage unit 10 Drug holding unit S Protective member of imaging unit a Long axis of capsule endoscope Length b Short axis length of capsule endoscope

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

  As a result of intensive studies in view of the above problems, the present inventor has a tablet capsule shape in which an objective lens, an illumination light source unit, a solid-state imaging device, and the like are integrally incorporated, and a surface portion A having a wetting index of 40 mN / m or more. It has been found that a capsule endoscope for medical use that can smoothly progress through the digestive organ and obtain a clear image in any of the digestive organs in the body cavity can be realized by using a capsule endoscope characterized by having It is up to the invention.

  First, the whole form of the capsule endoscope of the present invention will be described.

  FIG. 1 is an overall schematic view showing an example of an embodiment of a capsule endoscope of the present invention.

  As shown in FIG. 1, a capsule endoscope 1 according to the present invention is an ultra-small endoscope that moves independently from an operation means capable of wirelessly transmitting and receiving a so-called image. It is an endoscope, and an observation optical system is composed of an objective lens 2 and an image sensor 3 as an observation function means, and this image sensor 3 employs a fine CCD or CMOS in which one pixel is arranged at intervals of 0.1 μm to 3 μm. . Moreover, as the light emitting module 4 and the light source unit 5 constituting the illumination optical system, white, green, and red LEDs (hereinafter also referred to as LEDs) are commonly used. A protective member S is provided outside these observation optical system and illumination optical system. In the capsule endoscope of the present invention, the surface of the protective member S is preferably a surface portion A having a wetting index of 40 mN / m or more.

  The wireless transmission / reception antenna 8 is disposed on the opposite side of the illumination optical system together with the transmission means 6, the reception means 7, and the power storage means 10. The space portion 9 is a storage chamber for the chemical solution to be sent to the affected area, and in some cases, it is also a sample chamber for storing the living specimen sample of the affected area. The power storage means 10 may be a transformer that converts the illumination LED into a power source that emits light using an ultrasonic wave, a magnetic field, or an electric field transmitted from the outside.

  The system required for the capsule endoscope of the present invention is at least the observation optical system, the illumination optical system, the antenna system, and the transceiver system as described above. In addition, a power storage system that supplies energy, a DDS system, and a live inspection Sample collection system.

  The capsule endoscope has a roughly egg-shaped shape so that it can be quickly moved in the upper and lower digestive organs, and is preferably roughly elliptical from the top and side, but it is like a spherical or rugby ball type. It may be. In the case of a sphere, the closer to the sphere, the harder it is to control the posture, and it is necessary to devise shooting in a certain direction. In the capsule endoscope of the present invention, for example, by adopting an optical system as described in Japanese Patent Application Laid-Open No. 2001-174713, a desired part can be imaged. That is, according to the objective optical system, the total length of the optical system can be shortened by the combination of the reflecting surfaces or the combination of the reflecting surface and the refracting surface. Is realized. Further, by applying the objective optical system to the endoscope of the present invention, it is possible to obtain a small-sized endoscope capable of observation over the entire circumference in the circumferential direction orthogonal to the axial direction of the endoscope.

  As the aspect ratio of the capsule endoscope, when a cylinder circumscribing the capsule endoscope is first drawn and the volume of the cylinder is set to a minimum, as shown in FIG. 1, the diameter is set to the short axis of the capsule endoscope. If the length is b and the length of the cylinder is the long axis length a of the capsule endoscope, the a / b ratio is defined as the aspect ratio. The aspect ratio is preferably 1 or more and 2.3 or less. A particularly preferred range is 1 or more and 2 or less.

  As the objective lens 2 for forming an observation image on the CCD or CMOS which is the image pickup device 3, for example, an aspherical objective lens is arranged singly or in plural. Adoption of these aspherical lenses can reduce the number of lenses, so that the total length of the capsule portion can be shortened and swallowability can be improved.

  In the capsule endoscope of the present invention, a hydrophilic medium, which is a lubricating material, is applied or surface-treated on the outer surface of the capsule constituted by the capsule body. By this, when the capsule endoscope 1 is swallowed, the secretions in the digestive tract and the hydrophilic medium are compatible, and the lubricity between the capsule endoscope 1 and the digestive tract cavity is improved. It can move quickly without damaging the digestive tract, and as a result, a clear image can be obtained.

  The capsule endoscope 1 according to the present invention is an endoscope that is combined with an electric device that drives an imaging device 3 provided outside the body cavity, processes an output signal, and supplies power to the illumination unit 4, and a liquid crystal display device. The endoscope system which comprises an observation system and was imaged with the said image pick-up element 3 is displayed clearly on the liquid crystal monitor installed outside the body.

  Shooting and recording with a capsule endoscope is recorded on a small storage medium, image processing is performed, and a lesion is extracted to enable early detection. The electrical equipment is driven by a hospital power source or a household power source, a solar cell, a fuel cell, or the like.

  FIG. 2 is an overall schematic diagram showing another example of the embodiment of the capsule endoscope of the present invention.

  Basically, the configuration is the same as in FIG. 1, but in FIG. 2, the protective member S is not provided outside the observation optical system and the illumination optical system, and the objective lens 2 and the light source unit 5 are part of the outermost part. The surface of the objective lens 2 or the light source unit 5 is preferably a surface unit A having a wetting index of 40 mN / m or more.

  Next, details of the surface portion A having a wetting index of 40 mN / m or more according to the present invention will be described.

  As described above, the gastrointestinal tract is a strongly acidic environment with a pH close to 1 as an environment for degrading proteins. However, in a polymer having a carboxyl group as a hydrophilic group, a proton is imparted to the carboxyl group. Poor hydrophilicity in the environment. In contrast, polymers having functional groups such as alkylene oxide groups and hydroxy groups that are ionic dissociation even at pH 1 or ionic dissociation, such as sulfonic acid groups, have hydrophilicity even in strongly acidic environments. This is preferable because it can be maintained. However, if such a polymer is used, moisture and salt may permeate into the internal imaging electrical system through the polymer film, resulting in malfunction. The interior of the endoscope except for the outermost surface is water. It is preferable to comprise an impermeable polymer.

  The capsule endoscope of the present invention is characterized by having a surface portion with a wetting index of 40 mN / m or more.

  The wetting index in the present invention is a test method for evaluating the degree of hydrophilization, and a series of mixed solvents (for example, formamide and ethylene glycol monoethyl ether) whose surface tensions are different in order are used for the polymer member. The numerical value of the surface tension (mN / m) of the mixed solvent that was applied to the surface portion and was just determined to wet the surface of the polymer member was defined as the wetting index, and “wetting test method for polyethylene and polypropylene films” (JIS K 6768). In accordance with the method defined in 1., a commercially available wettability standard reagent of 31 mN / m to 54 mN / m (the higher the value, the more hydrophilic is improved) is immersed in a cotton swab and applied to the surface of the subject for measurement. .

  The polymer constituting the surface portion having a wetting index of 40 mN / m or more according to the present invention is not particularly limited, but is preferably a polymer having a nonionic group or an anionic group. Further, the nonionic group is preferably at least one selected from a single hydroxyl group, a sugar chain structure having a plurality of hydroxyl groups, and an alkylene oxide group, and the anionic group is a sulfonic acid group or a phosphoric acid group. Preferably there is.

  Examples of such polymers include acrylic acid alkyl esters such as methyl methacrylate, unsaturated olefin polymers such as ethylene, propylene, butadiene, and isoprene, and cycloolefin polymers copolymerized with these unsaturated olefins. Examples thereof include a single polymer of cycloolefin polymer such as norbornene resin, polycarbonates, styrene, vinyl acetate polymer, phenol resin, silicon resin and the like.

  When the polymer according to the present invention is treated in the presence of oxygen, a surface in which a hydrocarbon group on the polymer surface is substituted with a hydroxyl group can be obtained. After the surface is modified to have a hydroxyl group, it can be modified to have an alkylene oxide group by reacting with alkylene oxide or a derivative thereof. Further, a hydrophilic group can be treated by introducing a substituent having a sulfonic acid group using a hydroxyl group. With these surface modifications, favorable results can be obtained with modifications of about 1 nm to 1000 nm from the surface.

  In addition, since the polymers according to the present invention have low hydrophilicity, it is preferable to subject the surface to a hydrophilic treatment. Examples of the hydrophilic treatment include corona discharge treatment, plasma treatment, and arc discharge. There are treatments, flame treatments, etc., but from the viewpoint of the resulting hydrophilic effect and ease of imparting hydrophilicity, corona discharge treatment and plasma treatment are preferred.

  The corona discharge treatment is a treatment performed by applying a high voltage of 1 kV or higher between the electrodes at atmospheric pressure and discharging it, and is commercially available from Kasuga Electric Co., Ltd. and Toyo Electric Co., Ltd. It can be performed using an apparatus. The frequency used for the corona discharge treatment is a frequency of 20 kHz to 100 kHz, and a frequency of 30 kHz to 60 kHz is preferable. When the frequency is lowered, the uniformity of the corona discharge treatment is deteriorated, and unevenness of the corona discharge treatment occurs. In addition, when the frequency is increased, there is no particular problem when performing a high output corona discharge treatment, but when performing a low output corona discharge treatment, it becomes difficult to perform a stable treatment. Processing unevenness occurs.

  The plasma discharge treatment can be performed by exposing the polymer substrate to a high frequency discharge atmosphere in an argon or oxygen atmosphere with a plasma discharge treatment apparatus or the like. As an atmospheric pressure plasma treatment method, for example, an atmospheric pressure plasma discharge treatment method for applying a high-frequency pulse voltage described in JP-A Nos. 11-181573, 2000-26632, 2002-1109797, and the like can be used. .

  As an example of an application method of the capsule endoscope of the present invention, an endoscopy for early detection of cancer in the upper and lower digestive organs using the above-described endoscope observation system will be described. First, a doctor prepares an endoscope observation system, and prepares a subject who desires an examination to fast for 8 hours so as to drink a tablet of the capsule endoscope 1. Then, as it is administered into the oral cavity together with a small amount of water and moves quickly through the digestive organ, wireless transmission of images is started and storage of image data is started. In some cases, it is displayed on the screen of a liquid crystal monitor or home TV.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example 1
<< Preparation of capsule endoscope >>
[Preparation of capsule endoscope 101]
The objective lens, illumination light source unit, solid-state imaging device, etc. shown in FIG. 1 are integrally incorporated, and water-resistant gelatin obtained by crosslinking the protective member S with phenyl diisocyanate and partially hydrophobizing it is used. Used was a capsule endoscope 101 molded and attached with a thickness of 200 μm. The wetting index of the surface of the protective member made of this partially hydrophobized gelatin was 38 mN / m.

[Preparation of capsule endoscope 102]
The objective lens, the illumination light source unit, the solid-state imaging device, and the like shown in FIG. 1 are integrally incorporated, and the protective member S is polymethyl methacrylate (resin polymerized with a monomer manufactured by Mitsubishi Gas Chemical Company, abbreviated as PMMA). Was used to produce a capsule endoscope 102 molded and attached to a thickness of 200 μm. The wetting index of the surface of the protective member formed of this polymethyl methacrylate was 32 mN / m.

[Preparation of capsule endoscope 103]
The objective lens, the illumination light source unit, the solid-state imaging device, and the like shown in FIG. A capsule endoscope 103 that was molded and attached with the above was manufactured. The wetting index of the surface of the protective member formed with this norbornene resin was 32 mN / m.

[Preparation of capsule endoscopes 104 to 106]
In the production of the capsule endoscopes 101 to 103, a corona discharge treatment corresponding to 50% of the total area of the protective member S is performed for 1 second using a corona discharge treatment apparatus (manufactured by Kasuga Denki Co., Ltd.) at an output of 12 kV. Capsule endoscopes 104 to 106 were manufactured in the same manner except that the surface wetting index was set to 54 mN / m.

[Preparation of capsule endoscope 107]
In the manufacture of the capsule endoscope 104, the capsule endoscope 107 is similarly manufactured except that the water-resistant gelatin obtained by crosslinking the member of the protective member S with phenyl diisocyanate is changed to polypropylene resin (abbreviated as PP). Was made.

[Preparation of capsule endoscope 108]
In the manufacture of the capsule endoscope 104, the capsule endoscope 108 is similarly manufactured except that the water-resistant gelatin obtained by crosslinking the member of the protective member S with phenyl diisocyanate is changed to polyethylene resin (abbreviated as PE). Was made.

[Preparation of capsule endoscopes 109 to 113]
In the production of the capsule endoscopes 104 to 108, a plasma treatment apparatus (output: 500 W, generation source: 2.45 GHz micro) manufactured by Shibaura Mechatronics Co., Ltd. was used instead of corona discharge treatment for 50% of the total area of the protective member S. Capsule endoscopes 109 to 113 were manufactured in the same manner except that plasma treatment was performed using a wave and a treatment pressure of 40 Pa (0.3 Torr) so that the surface wetting index was 54 mN / m.

[Preparation of capsule endoscopes 114 to 119]
In the production of the capsule endoscope 110 (matrix polymer: PMMA), after performing the plasma treatment, the treatment area of the following E treatment was changed in the same manner as described in Table 1, Capsule endoscopes 114-119 were produced.

  E-treatment: The surface of PMMA was alkali-hydrolyzed with a sodium hydroxide solution having a pH of 12, and then polyoxyethylenated with ethylene oxide (repeating unit 6).

[Preparation of capsule endoscopes 120 to 122]
In the production of the capsule endoscope 119 (processing area: 100%), the capsule endoscope was changed in the same manner except that instead of the E conversion process, the following T conversion process, S conversion process, and P conversion process were performed. Mirrors 120-122 were made.

  T-treatment: After alkaline hydrolysis of the PMMA surface with a sodium hydroxide solution having a pH of 12, hydroxyethyl cellulose was dissolved in a methyl ethyl ketone solvent, applied to a thickness of 1.0 μm, and dried to form a sugar chain structure.

  S conversion treatment: The PMMA surface was alkali-hydrolyzed with a sodium hydroxide solution having a pH of 12, followed by sulfonation treatment with sulfonic acid.

  P-treatment: The surface of PMMA was alkali-hydrolyzed with a sodium hydroxide solution having a pH of 12, and then phosphorylated with phosphoric acid.

[Preparation of capsule endoscope 123]
In the production of the capsule endoscope 107 (matrix polymer: PP), after the corona discharge treatment, E treatment (previous treatment, treated area: 100%) was performed in the same manner. The endoscope 123 was produced.

<< Evaluation of capsule endoscope >>
[Measurement of surface wetting index]
The surface of the protective member of each capsule endoscope produced as described above was measured for the wetting index according to the following method.

  In accordance with the method defined in “Wetting Test Method for Polyethylene and Polypropylene Film” (JIS K 6768), a commercially available wettability standard reagent 31 mN / m to 54 mN / m (the higher the value, the higher the hydrophilicity) is swab It was dipped in, applied to the surface of the subject, the surface temperature was kept at 37 ° C., and the value after 0.5 seconds was measured. At this time, the wetness index was defined as the minimum value of the well-wet reagent number without water repellency.

[Evaluation of durability]
Each capsule endoscope produced above was thawed from the bovine gastric juice that had been collected in advance and stored frozen, soaked in this gastric juice for 1 hour, and then sent and received to check whether there was any abnormality. evaluated. A case where transmission was possible without any abnormality was judged as ◯, and a case where transmission failure occurred was judged as X.

[Evaluation of sharpness of photographed image]
Each capsule endoscope produced above is moved in the simulated body from the stomach part of the human body to the small intestine, and a captured image is transmitted at the time of movement, and the sharpness of the taken captured image is visually observed, and the captured image is observed according to the following criteria: The clarity of the images was evaluated.

5: The transmitted photographed image is a very clear and good image with no adhering matter to the protective member. 4: The transmitted photographed image is a clear image with no foreign matter adhering to the protective member. : Slightly lower sharpness is observed in the transmitted photographed image due to a part adhering to the protective member, but the image quality can withstand practically. 2: In the transmitted photographed image Deterioration of sharpness due to foreign matter adhering to the protective member is recognized and is lower than a practically acceptable image quality level. 1: A large amount of foreign matter adhering to the protective member is recognized in the transmitted photographed image. Table 1 shows the results obtained by the above-mentioned results that the image quality is unacceptable for practical use.

  As is apparent from the results shown in Table 1, the capsule endoscope of the present invention having a surface portion with a wetting index of 40 mN / m or more is in a state of being stored for a long time in a strong acid environment as compared with the comparative example. It can be seen that it has excellent durability and excellent adhesion resistance of the substance in the body cavity to the protective member at the imaging site, and transmits an extremely clear image.

Example 2
As shown in FIG. 2, the configuration of the observation optical system and the illumination optical system is such that the light source cover (made of norbornene resin) and the objective lens (made of norbornene resin) are arranged on the outermost surface, and the light source cover and the objective lens surface are examples. The capsule endoscopes 204 to 223 are manufactured in the same manner except that the same surface treatment as that for the manufacture of the capsule endoscopes 104 to 123 is performed, and the durability and photographing are performed in the same manner as the method described in the first embodiment. As a result of evaluating the sharpness of the image, the same excellent results as in Example 1 could be obtained.

Claims (7)

A capsule endoscope having a surface portion A having a wetting index of 40 mN / m or more. The capsule endoscope according to claim 1, wherein the surface portion A is a protective member of an imaging unit that houses a lens and an illuminating body. The capsule endoscope according to claim 1, wherein the surface portion A is a lens surface or an illuminator surface. The capsule endoscope according to any one of claims 1 to 3, wherein the surface portion A is subjected to corona discharge treatment or plasma discharge treatment. The capsule endoscope according to any one of claims 1 to 4, wherein the material constituting the surface portion A is a polymer having a nonionic group or an anionic group. The capsule endoscope according to claim 5, wherein the nonionic group is at least one selected from a single hydroxyl group, a sugar chain structure having a plurality of hydroxyl groups, and an alkylene oxide group. The capsule endoscope according to claim 5, wherein the anionic group is a sulfonic acid group or a phosphoric acid group.